function dateFormat(dtStr){

    const dt = new Date(dtStr)

    const y = dt.getFullYear()
    const m = padZero(dt.getMonth()+1)
    const d = padZero(dt.getDate())

    const hh = padZero(dt.getHours())
    const mm = padZero(dt.getMinutes())
    const ss = padZero(dt.getSeconds())

    return `${y}-${m}-${d} ${hh}:${mm}:${ss}`
}
// 补零
function padZero(n){
    return n > 9 ? n :'0'+n
}
module.exports={
    dateFormat
}